Process of making wood-pulp.



No. 738,633. f PATBNTED MM2, 1905.

l G. s; GUSHING. PROCESS 0PMAK1NG'wooD PULP. Y

4 APPLICATION FILED 0013.15. 1903.

`I1 SHEETB--SHEET l.

PHP u xm By l Attorneys 'Nm-788,633. f v PATPNTPD MAY z, 1905.

G. s. GUSHING. l PRooPss oP MAKING woon PULP.

APPLICATION FILED 00T. 15. 1903.

' 4 SHEETS-SHEET' 2.

tnsses: I /egyye [Vas/@7% lnventor No. 788,633. PATENTE-D MAY 2, 1905.

f G. S. GUSHING.

PROCESS OP MAKING WOUD PULP.

APPLICATION FILED DUT.15, 1903.

4 SHEETS-SHEET 3.

5r? l y 5f 5p 'I Cr.. 5

Witnesses: (Yggfye HCMS/w'my, Inventor,

" Attorneys No. 788,638. PATENTED MAY 2, 1905. G. S. GUSHING.

PROCESS OF MAKING WOOD PULP.

APPLICATION FILED 00T.15, 1903.

4 SHEETS-SHEET 4.

Y Witnesses: gewyeQVM/'my Inventor,

Attorneys ivo. 'reses-:3.

atented May Q, 1905.

PATENT OFFICE.

GEORGE SOAMMELL OUSHING, OF ST. JOHN, CANADA.

PROCESS OF MAKING WOOD-PULP.

SPECIFICATON forming part of Letters Patent No. 788,633, dated May 2, 1905.

Appimuon filed ogetti 15, ,1903. serial No. 177,105.

To @ZZ whom it may concern.-

Be it known that I, GEORGE SCAMMELL CUSH- ING, residing' at St. John; inA the county of St. John, in the Province of New Brunswick, in the Dominion of Canada, have invented certain new and useful Improvements inProcesses of MakingVood-Pulp; and Ido hereby declare that the following is a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates tothe process of producing wood-pulp by mechanical means; and its object is to produce a pulp of superior quality in a simple apparatus with a minimum expenditure of power. While the process for this purpose usually consists in grindinglogs of pulp-wood under great pressure, the present invention contemplates using refuse wood of any size, bark, sawdust, Sac., as a raw material, which operates advantageously for the economy of the process. The present invention contemplates the reduction of this refuse wood to small chips in a suitable chopping-mill, and the resulting small chips are then steamed in a suitable apparatus and thereafter are ground in a grinding-mill of special construction. In this manner a pulp is produced of line quality and of heavy fibrous nature especially adapted for making good brown paper or cardboard without the addition of other fibrous material.

The invention consist in those steps and operations to be described more fully hereinafter, and definitely set forth in the claim.

ln the drawings which fully illustrate the apparatus by which I carry out my process, Figure 1 is substantially a vertical section through a chopping-mill in which the refuse or raw wood is reduced. Fig. 2 is an elevation of the grinding-mill, certain parts being' shown in section,as will appear. Fig. 3 is avertical section through this grinding-mill. Fig. It is a vertical central section through a digester in which the chips are steamed preparatory to their treatment in the grinding-mill. Fig'. is a view representing the grinding-mill in end elevation, this view being substantially a section on the line 5 5 of Fig. 2. Fig. 6 is a vertical section taken substantially on the line 6 6 of Fig. 8 and representing a portion of the regulating apparatus of the grinding-mill. Fig. 7 is a bottom plan view of one of the grinding-stones of the grinding-mill. Fig. 8 is a plan of the grinding-millgrepresen ting the feeding-hopper above the same as removed. Fig. 9 is a view representing in perspective a detail of the grinding-mill. Fig. 10 is a vertical section taken substantially on the line 10 10 of Fig. 8 and representing the central portion of the grinding-mill upon an enlarged scale. Fig. 11 is a section through a part of one of the grinding-stones, the View being upon a much enlarged scale, as will appear.

Throughout the drawings and specification the same numerals ofreference denote like parts.

Proceeding now to a more detailed description of my process and the apparatus by means of which it is effected, 1 represents a chopping-mill of any suitable construction in which the raw wood may be reduced to small particles or chips. As represented, this mill may be mounted upon a suitable foundation Q, which supports a basin 3 of circular form, in connection with which there is arranged a centrally-disposed vertical shaft 4, as shown, and the bottom of this shaft is carried in a suitable step-bearing 5, and a suitable bushing 6 is provided within the basin, as indicated. A cross head or axle 7 is carried by the vertical shaft 4, and at the extremities of this axle 7 heavy rollers or wheels 8 are mounted, the faces of the same being provided with knives 9 for the purpose of chopping and reducing the raw material 10, which is placed withinthe basin for that purpose. After the raw material has been reduced to the form of small chips or blocks these chips are introduced into a digestcr 11, (shown in Fig. 4,) and this digester may consist of a cylindrical body having a perforated false bottom 12, upon which the chips 13 are placed. Steam is admitted to the digester through a pipe 14E, including a suitable con trolling-valve 15, and the chips are subjected to this treatment until thoroughly steamed, the water of condensation finding outlet through the aforesaid false bottom, near which in the bottom of the digester is attached an outlet-pipe 16 with a valve 17. It should be stated that the steam used in the digester is preferably at substantially eighty pounds pressure to the square inch. After being thoroughly steamed in the manner suggested the chips are brought to the grinding-mill. (Shown most fully in Fig. 3.) This grinding-mill is mounted upon a suitable frame 18 and comprises a stationary upper stone 19 and a lower rotatable stone 20, the latter being carried upon the upper extremity of a vertical shaft 21, driven by suitablegearing 22 and a belt-wheel 23, the latter part of this mechanism being carried in the lower portion of the frame, as shown. The grinding-stones 19 and 20 are preferably disposed at substantially the level of the floor 24, said floor being provided with a large opening about the stones, in which opening there is placed an annular cup or trough 25, which is adapted to receive the pulp from the periphery of the stones. This cup or trough may be inclosed in a suitable casing or frame 26. The lower stone 20 is preferably securely mounted in any suitable manner upon a base-plate 27, the same being securely attached to the Lipper extremity of the shaft 21, as will be readily understood. These stones are prefverabl y of circular form and disposed a short distance apart, which distance is capable of being regulated in a mannerwhich will appear more fully hereinafter. The upper stone 19 is attached, by means of suitable bolts 28, to the under side of a pair of oppositely-disposed beams 29. As indicated most clearly in Fig. 8, these beams project beyond the periphery of the stone and near their extremities are provided with brackets 30, attached to their upper sides, which brackets overhang the edges of the beams, as shown, projecting toward a central line between the beams. The overhanging portion of these brackets constitute bearings 31, in which eccentric shafts 32 are rotatably mounted. One of these shafts is most clearly shown in Fig. 9. It should be understood that the bearings 3l of the brackets 30 are double, and the eccentric shafts 32 at the points between the parts of the bearings 31 are formed with enlarged heads 33 of round form, and these heads 33 are rotatably mounted in the upper extremities of links 34, which links are pivotally attached at their lower extremities to base-plates 35, the said base-plates being attached to the floor 24, as shown. At one extremity these eccentric shafts 32 carry rigidly segments 36, between which there is disposed a worm-shaft 37, comprising worms 38, which mesh, respectively, with these two segments, portions of this shaft 37 being rotatably mounted in bearings or brackets 39, attached to the extremities of the beams 29, as shown. The projecting extremity of the worm-shaft 37 is provided with a suitable crank 40 for the purpose of rotating the worm-shaft and imparting a rotary movement to the eccentric shafts by reason of the segments 36. Evidently such a rotation of the eccentric shafts would either raise or lower the upper stone 19, depending upon the angular position of the eccentric heads 33, as will be readily understood.

The upper stone 19 aforesaid is provided with a central opening 41, which may be of substantially square form, as shown, and above this opening there is disposed a hopper 42 of any suitable construction adapted to receive the chips 13 from the digester, and over this hopper there is arranged a faucet or valve 43, enabling water to be vsupplied to the hopper through a pipe 44. It should be understood that the material to be ground passes from the hopper through the opening 41 and arriving upon the face of the lower stone 2O it is ground to a pulp\at the same time that it moves progressively toward the periphery of the grinding stones. In order to improve the efficiency of the actual grinding operation, the lower face of the upper stone is provided with a plurality of curved grooves or channels 45, preferably of the form shown in Fig. ll and which are of increasing depth toward the center of the stone, as will be readily understood. These grooves preferably curve forwardly with reference to the'direction of rotation of the lower stone, which direction is indicated by an arrow at the right of Fig. 7. This arrangement operates to effect a certain feeding orprogressive movement of the material toward the periphery of the stone. At the proper points the stone is provid ed with bolt holes or openings 46, together with recesses 47, in which the heads of the bolts 28 may be countersunk. In order to further facilitate thev progressive or feeding movement of the material toward the periphery of the'stones just beneath the aforesaid opening 41, the upper face of the lower stone is provided with a feeder 48, which feeder is preferably of substantially the form shown most clearly in Figs. 8 and 10. It consists of a narrow plate or bar bent Vinto the shape of a rudely-formed S, and this feeder is attached, by means of suitable screws 49, at the central portion of the stone. This feeder is disposed so that its extremities incline toward the rear with reference to the direction of rotation of the stone, which direction is indicated by the arrow in Fig. 10, which is placed adjacent to the feeder.

In carrying out the process after the chips are taken from the digester, having been thoroughly steamed therein, they are fed to the hopper 42, and the grinding or pulping operation begins. They should be fed to this hopper fresh from the digesterwthat is, at a high temperature and substantially the condition v which they are in within the digester. As the grinding operation takes place suitable quantities of water may be supplied through the pipe 44, which water immediately iinds its way to the face of the grinding-stone, fa-

IOO

cilitating the pulping operation. ltis thought sist in producing the Wood-pulp without presthat the expanded condition of the wood, due

especially toits finely-divided condition, operates very advantageously toward producing a pulp of a highly-fibrous nature, and the absence of pressure during the grinding operation is considered also a Very important fea ture, operating for the same end. It should be stated also that itis preferable to use green wood, as it produces superior results.

The pulp produced hy this process is much superior in quality to that produced by the ordinary pulp produced mechanically from steamed logs by grinding them under pressure. l/Vith the present process the liber of the pulp produced is long and soft and well adapted for the uses of pulp. The power required with this process does not exceed ten per cent. of the power required where the wood is ground under great pressure, as in the present instance there is no high frictional resistance to be overcome.

The essential features of my process consure and grinding the material while hot and fresh from the digester in connection with the manner of adapting the faces of the stones for their work.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s-

The herein-described process of producing woodpulp, which consists in reducing the wood to the condition of small chips or blocks, subjecting the same to the action of steam under pressure and expanding' the chips, then removing the same while hot to a grinder and grinding the same without pressure, adding water during the progress of the grinding', thereby producinga highly-librous soft pulp.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

GERGE SCAMMELL CUSHING.

Witnesses:

ALEXANDER PERLEY BAMHILL, CHARLES FENsoN SANFORD. 

